This is Ulvar of Icepeople from Icepeople book series by Margit Sandemo. His mother is a woman named Saga Simon. His father is Lucifer, the king of black angels (not the devil, in Margit Sandemo's books Lucifer and the devil are two different persons). Ulvar has a brother named Marco. Enchanted by the evil powers, Ulvar did many bad things. But he is still my favourite character in the series because after his death at 21 he became a spirit and succeeded to free himself.